Monoclonal antibody therapy in COVID-19.

Acute severe respiratory syndrome coronavirus-2 (SARS-CoV-2) infection causes coronavirus disease-2019 (COVID-19) which is associated with inflammation, thrombosis edema, hemorrhage, intra-alveolar fibrin deposition, and vascular and pulmonary damage. In COVID-19, the coronavirus activates macrophages by inducing the generation of pro-inflammatory cytokines [interleukin (IL)-1, IL-6, IL-18 and TNF] that can damage endothelial cells, activate platelets and neutrophils to produce thromboxane A2 (TxA2), and mediate thrombus generation. In severe cases, all these phenomena can lead to patient death. The binding of SARS-CoV-2 to the Toll Like Receptor (TLR) results in the release of pro-IL-1ß that is cleaved by caspase-1, followed by the production of active mature IL-1ß which is the most important cytokine in causing fever and inflammation. Its activation in COVID-19 can cause a "cytokine storm" with serious biological and clinical consequences. Blockade of IL-1 with inhibitory and anti-inflammatory cytokines represents a new therapeutic strategy also for COVID-19. Recently, very rare allergic reactions to vaccines have been reported, with phenomena of pulmonary thrombosis. These side effects have raised substantial concern in the population. Highly allergic subjects should therefore be vaccinated under strict medical supervision. COVID-19 has accelerated vaccine therapy but also the use of drugs and monoclonal antibodies (mABs) which have been used in COVID-19 therapy. They are primarily adopted to treat high-risk mild-to-moderate non-hospitalized patients, and it has been noted that the administration of two mABs gave better results. mABs, other than polyclonal plasma antibodies from infected subjects with SARS-CoV-2, are produced in the laboratory and are intended to fight SARS-CoV-2. They bind specifically to the antigenic determinant of the spike protein, inhibiting the pathogenicity of the virus. The most suitable individuals for mAB therapy are people at particular risk, such as the elderly and those with serious chronic diseases including diabetics, hypertension and obesity, including subjects suffering from cardiovascular diseases. These antibodies have a well-predetermined target, they bind mainly to the protein S (formed by the S1A, B, C and D subtypes), located on the viral surface, and to the S2 protein that acts as a fuser between the virus and the cell membrane. Since mABs are derived from a single splenic immune cell, they are identical and form a cell clone which can neutralize SARS-CoV-2 by binding to the epitope of the virus. However, this COVID-19 therapy may cause several side effects such as mild pain, bleeding, bruising of the skin, soreness, swelling, thrombotic-type episodes, arterial hypertension, changes in heart activity, slowed bone marrow activity, impaired renal function, diarrhea, fatigue, nausea, vomiting, allergic reaction, fever, and possible subsequent infection may occur at the site of injection. In conclusion, the studies promoting mAB therapy in COVID-19 are very promising but the results are not yet definitive and more investigations are needed to certify both their good neutralizing effects of SARS-CoV-2, and to eliminate, or at least mitigate, the harmful side effects.

The British variant of the new coronavirus-19 (Sars-Cov-2) should not create a vaccine problem.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a highly contagious virus that infects humans and a number of animal species causing coronavirus disease-19 (COVID-19), a respiratory distress syndrome which has provoked a global pandemic and a serious health crisis in most countries across our planet. COVID-19 inflammation is mediated by IL-1, a disease that can cause symptoms such as fever, cough, lung inflammation, thrombosis, stroke, renal failure and headache, to name a few. Strategies that inhibit IL-1 are certainly helpful in COVID-19 and can represent one of the therapeutic options. However, until now, COVID-19 therapy has been scarce and, in many cases, ineffective, since there are no specific drugs other than the vaccine that can solve this serious health problem. Messenger RNA (mRNA) vaccines which are the newest approach, are already available and will certainly meet the many expectations that the population is waiting for. mRNA vaccines, coated with protected soft fatty lipids, use genetic mRNA (plus various inactive excipients) to make a piece of the coronavirus spike protein, which will instruct the immune system to produce specific antibodies. The soft fatty lipids allow the entry of mRNA into cells where it is absorbed into the cytoplasm and initiates the synthesis of the spike protein. In addition, vaccination also activates T cells that help the immune system respond to further exposure to the coronavirus. mRNA induces the synthesis of antigens of SARS-CoV-2 virus which stimulate the antibody response of the vaccinated person with the production of neutralizing antibodies. The new variant of the coronavirus-19 has been detected in the UK where, at the moment, the London government has imposed a lockdown with restrictions on international movements. The virus variant had already infected 1/4 of the total cases and in December 2020, it reached 2/3 of those infected in the UK. It has been noted that the spreading rate of the British variant could be greater than 70% of cases compared to the normal SARS-CoV-2 virus, with an R index growth of 0.4. Recent studies suggest that coronavirus-19 variation occurs at the level N501Y of the spike protein and involves 23 separate mutations on the spike, 17 of which are linked to the virus proteins, thus giving specific characteristics to the virus. In general, coronaviruses undergo many mutations that are often not decisive for their biological behavior and does not significantly alter the structure and the components of the virus. This phenomenon also occurs in SARS-CoV-2. It is highly probable that the variants recently described in the UK will not hinder vaccine-induced immunity. In fact, the variant will not break the vaccine although it may have some chance of making it a little less effective. Therefore, it is pertinent to think that the vaccine will work against the SARS-CoV-2 variant as well. In today's pandemic, the D614G mutation of the amino acid of corronavirus-19, which emerged in Europe in February 2020 is the most frequent form and causes high viral growth. The previously infrequent D614G mutation is now globally dominant. This variant, which is being tested by many international laboratories, is rapidly spreading across the countries and a series of vaccinated subjects are testing to see if their antibodies can neutralize the new variant of SARS-CoV-2. This variant has a very high viral growth and is less detectable with the RT-PCR technique in the laboratory. It has been reported that the British variant that increases viral load does not cause more severe effects in the respiratory tract and lung disease, therefore, it is certain that the variant is growing rapidly and must be kept under control; for this reason, laboratory data is expected impatiently. The study on the many variants that coronavirus-19 presents is very interesting and complete and clearer data on this topic will be ready in the near future. In addition, it is still unclear whether the different variants discovered in many countries, including Africa, share the same spike protein mutation and therefore, this is another study to elaborate on. In order to be certain and to not have unexpected surprises, we need to reduce the spread and the transmission speed of viral variants that could appear around the world, creating new pandemics. For this reason, the scientific community is on the alert since laboratory tests on serum antibodies from COVID-19 survivors have been reported to be less effective in attacking the variant. In light of the above, the scientific community must be on the alert as larger variants of the spike protein could escape vaccine-induced antibodies, which for now are of great help to the community and can save millions of lives. Deepening the study of spike protein mutations will help to better understand how to combat coronavirus-19 and its variants.

Coronavirus-19 (SARS-CoV-2) induces acute severe lung inflammation via IL-1 causing cytokine storm in COVID-19: a promising inhibitory strategy.

SARS-Cov-2 infection causes local and systemic inflammation mediated by pro-inflammatory cytokines and COX-2 eicosanoid products with metabolic dysfunction and tissue damage that can lead to patient death. These effects are primarily induced by IL-1 cytokines, which are involved in the elevation of hepatic acute phase proteins and fever. IL-1 has a broad spectrum of biological activities and participates in both innate and acquired immunity. In infections, IL-1 induces gene expression and synthesis of several cytokines/chemokines in both macrophages and mast cells (MCs). The activation of MCs triggers the secretion of mediators stored in the granules, and the de novo synthesis of pro-inflammatory cytokines. In microorganism infections, the release of IL-1 macrophage acts on adhesion molecules and endothelial cells leading to hypotension and septic shock syndrome. IL-1 activated by SARS-CoV-2 stimulates the secretion of TNF, IL-6 and other cytokines, a pro-inflammatory complex that can lead to cytokine storm and be deleterious in both lung and systemically. In SARS-CoV-2 septic shock, severe metabolic cellular abnormalities occur which can lead to death. Here, we report that SARS-CoV-2 induces IL-1 in macrophages and MCs causing the induction of gene expression and activation of other pro-inflammatory cytokines. Since IL-1 is toxic, its production from ubiquitous MCs and macrophages activated by SARS-CoV-2 can also provokes both gastrointestinal and brain disorders. Furthermore, in these immune cells, IL-1 also elevates nitric oxide, and the release of inflammatory arachidonic acid products such as prostaglndins and thromboxane A2. All together these effects can generate cytokine storm and be the primary cause of severe inflammation with respiratory distress and death. Although, IL-1 administered in low doses may be protective; when it is produced in high doses in infectious diseases can be detrimental, therefore, IL-1 blockade has been studied in many human diseases including sepsis, resulting that blocking it is absolutely necessary. This definitely nurtures hope for a new effective therapeutic treatment. Recently, two interesting anti-IL-1 cytokines have been widely described: IL-37 and IL-1Ra. IL-37, by blocking IL-1, has been observed to have anti-inflammatory action in rodents in vivo and in transfected cells. It has been reported that IL-37 is a very powerful protein which inhibits inflammation and its inhibition can be a valid therapeutic strategy. IL-37 is a natural suppressor of inflammation that is generated through a caspase-1 that cleaves pro-IL-37 into mature IL-37 which translocates to the nucleus and inhibits the transcription of pro-inflammatory genes; while IL-1Ra inhibits inflammation by binding IL-1 to its IL-1R (receptor). We firmly believe that blocking IL-1 with an anti-inflammatory cytokine such as IL-37 and/or IL-1Ra is an effective valid therapy in a wide spectrum of inflammatory disorders including SARS-CoV-2-induced COVID-19. Here, we propose for the first time that IL-37, by blocking IL-1, may have an important role in the therapy of COVID-19.

Mast cells activated by SARS-CoV-2 release histamine which increases IL-1 levels causing cytokine storm and inflammatory reaction in COVID-19.

SARS-CoV-2 virus is an infectious agent commonly found in certain mammalian animal species and today also in humans. SARS-CoV-2, can cause a pandemic infection with severe acute lung injury respiratory distress syndrome in patients with COVID-19, that can lead to patient death across all ages. The pathology associated with pandemic infection is linked to an over-response of immune cells, including virus-activated macrophages and mast cells (MCs). The local inflammatory response in the lung that occurs after exposure to SARS-CoV-2 is due to a complex network of activated inflammatory innate immune cells and structural lung cells such as bronchial epithelial cells, endothelial cells and fibroblasts. Bronchial epithelial cells and fibroblasts activated by SARS-CoV-2 can result in the up-regulation of pro-inflammatory cytokines and induction of MC differentiation. In addition, endothelial cells which control leukocyte traffic through the expression of adhesion molecules are also able to amplify leukocyte activation by generating interleukin (IL)-1, IL-6 and CXC chemokines. In this pathologic environment, the activation of mast cells (MCs) causes the release of histamine, proteases, cytokines, chemokines and arachidonic acid compounds, such as prostaglandin D2 and leukotrienes, all of which are involved in the inflammatory network. Histamine is stored endogenously within the secretory granules of MCs and is released into the vessels after cell stimulation. Histamine is involved in the expression of chemokine IL-8 and cytokine IL-6, an effect that can be inhibited by histamine receptor antagonists. IL-1 is a pleiotropic cytokine that is mainly active in inflammation and immunity. Alveolar macrophages activated by SARS-CoV-2 through the TLR produce IL-1 which stimulates MCs to produce IL-6. IL-1 in combination with IL-6 leads to excessive inflammation which can be lethal. In an interesting study published several years ago (by E. Vannier et al., 1993), it was found that histamine as well as IL-1 are implicated in the pathogenesis of pulmonary inflammatory reaction, after micorganism immune cell activation. IL-1 in combination with histamine can cause a strong increase of IL-1 levels and, consequently, a higher degree of inflammation. However, it has been reported that histamine alone has no effect on IL-1 production. Furthermore, histamine enhances IL-1-induced IL-6 gene expression and protein synthesis via H2 receptors in peripheral monocytes. Therefore, since MCs are large producers of histamine in inflammatory reactions, this vasoactive amine, by increasing the production of IL-1, can amplify the inflammatory process in the lung infected with SARS-CoV-2. Here, we have proposed for the first time an emerging role for histamine released by MCs which in combination with IL-1 can cause an increase in lung inflammation induced by the viral infection SARS-CoV-2.

IL-1 induces throboxane-A2 (TxA2) in COVID-19 causing inflammation and micro-thrombi: inhibitory effect of the IL-1 receptor antagonist (IL-1Ra).

IL-1 induces a significant number of metabolic and hematological changes. In experimental animals, IL-1 treatments cause hypotension due to rapid reduction of systemic blood pressure, reduced vascular resistance, increased heart rate and leukocyte aggregations. IL-1 causes endothelial dysfunction, the triggering factor of which may be of a different nature including pathogen infection. This dysfunction, which includes macrophage intervention and increased protein permeability, can be mediated by several factors including cytokines and arachidonic acid products. These effects are caused by the induction of IL-1 in various pathologies, including those caused by pathogenic viral infections, including SARS-CoV-2 which provokes COVID-19. Activation of macrophages by coronavirus-19 leads to the release of pro-inflammatory cytokines, metalloproteinases and other proteolytic enzymes that can cause thrombi formation and severe respiratory dysfunction. Patients with COVID-19, seriously ill and hospitalized in intensive care, present systemic inflammation, intravascular coagulopathy with high risk of thrombotic complications, and venous thromboembolism, effects mostly mediated by IL-1. In these patients the lungs are the most critical target organ as it can present an increase in the degradation products of fibrin, fibrinogen and D-dimer, with organ lesions and respiratory failure. It is well known that IL-1 induces itself and another very important pro-inflammatory cytokine, TNF, which also participates in hemodynamic states, including shock syndrome in COVID-19. Both IL-1 and TNF cause pulmonary edema, thrombosis and bleeding. In addition to hypotension and resistance of systemic blood pressure, IL-1 causes leukopenia and thrombocytopenia. The formation of thrombi is the main complication of the circulatory system and functionality of the organ, and represents an important cause of morbidity and mortality. IL-1 causes platelet vascular thrombogenicity also on non-endothelial cells by stimulating the formation of thromboxane A2 which is released into the inflamed environment. IL-1 is the most important immune molecule in inducing fever, since it is involved in the metabolism of arachidonic acid which increases from vascular endothelial organs of the hypothalamus. The pathogenesis of thrombosis, vascular inflammation and angigenesis involves the mediation of the activation of the prostanoid thromboxane A2 receptor. In 1986, in an interesting article (Conti P, Reale M, Fiore S, Cancelli A, Angeletti PU, Dinarello CA. In vitro enhanced thromboxane B2 release by polymorphonuclear leukocytes and macrophages after treatment with human recombinant interleukin 1. Prostaglandins. 1986 Jul;32(1):111-5), we reported for the first time that IL-1 induces thromboxane B2 (TxB2) releases in activated neutrophils and macrophages. An increase in thromboxane can induce leukocyte aggregation and systemic inflammation, which would account for the dramatic thrombi formation and organ dysfunction. Hence, IL-1 stimulates endothelial cell-leukocyte adhesion, and TxB2 production. All these events are supported by the large increase in neutrophils that adhere to the lung and the decrease in lymphocytes. Therefore, ecosanoids such as TxA2 (detected as TxB2) have a powerful action on vascular inflammation and platelet aggregation, mediating the formation of thrombi. The thrombogenesis that occurs in COVID-19 includes platelet and cell aggregation with clotting abnormalities, and anti-clotting inhibitor agents are used in the prevention and therapy of thrombotic diseases. Prevention of or induction of TxA2 avoids thrombi formation induced by IL-1. However, in some serious vascular events where TxA2 increases significantly, it is difficult to inhibit, therefore, it would be much better to prevent its induction and generation by blocking its inductors including IL-1. The inhibition or lack of formation of IL-1 avoids all the above pathological events which can lead to death of the patient. The treatment of innate immune cells producing IL-1 with IL-1 receptor antagonist (IL-1Ra) can avoid hemodynamic changes, septic shock and organ inflammation by carrying out a new therapeutic efficacy on COVID-19 induced by SARS-CoV-2.

SARS-CoV-2, which induces COVID-19, causes kawasaki-like disease in children: role of pro-inflammatory and anti-inflammatory cytokines.

Acute severe respiratory syndrome coronavirus-2 (SARS-CoV-2) caused a global pandemic coronavirus disease 2019 (COVID-19). In humans, SARS-CoV-2 infection leads to acute respiratory distress syndrome which presents edema, hemorrhage, intra-alveolar fibrin deposition, and vascular changes characterized by thrombus formation, micro-angiopathy and thrombosis. These clinical signs are mediated by pro-inflammatory cytokines. In recent studies it has been noted that COVID-19 pandemic can affect patients of all ages, including children (even if less severely) who were initially thought to be immune. Kawasaki disease is an autoimmune acute febrile inflammatory condition, which primarily affects young children. The disease can present immunodeficiency with the inability of the immune system to fight inflammatory pathogens and leads to fever, rash, alterations of the mucous membranes, conjunctiva infection, pharyngeal erythema, adenopathy, and inflammation. In the COVID-19 period, virus infection aggravates the condition of Kawasaki disease, but it has also been noted that children affected by SARS-V-2 may develop a disease similar to Kawasaki's illness. However, it is uncertain whether the virus alone can give Kawasaki disease-like forms. As in COVID-19, Kawasaki disease and its similar forms are mediated by pro-inflammatory cytokines produced by innate immunity cells such as macrophages and mast cells (MCs). In light of the above, it is therefore pertinent to think that by blocking pro-inflammatory cytokines with new anti-inflammatory cytokines, such as IL-37 and IL-38, it is possible to alleviate the symptoms of the disease and have a new available therapeutic tool. However, since Kawasaki and Kawasaki-like diseases present immunodeficiency, treatment with anti-inflammatory/immunosuppressant molecules must be applied very carefully.

How to reduce the likelihood of coronavirus-19 (CoV-19 or SARS-CoV-2) infection and lung inflammation mediated by IL-1.

SARS-CoV-2, also referred to as CoV-19, is an RNA virus which can cause severe acute respiratory diseases (COVID-19), with serious infection of the lower respiratory tract followed by bronchitis, pneumonia and fibrosis. The severity of the disease depends on the efficiency of the immune system which, if it is weak, cannot stem the infection and its symptoms. The new CoV-19 spreads in the population at a rate of 0.8-3% more than normal flu and mostly affects men, since immune genes are more expressed on the X chromosome. If CoV-19 would spread with a higher incidence rate (over 10%), and affect the people who live in closed communities such as islands, it would cause many more deaths. Moreover, people from the poorest classes are most at risk because of lack of health care and should be given more assistance by the competent authorities. To avoid the aggravation of CoV-19 infection, and the collapse of the health system, individuals should remain at home in quarantine for a period of approximately one month in order to limit viral transmission. In the case of a pandemic, the severe shortage of respirators and protective clothing, due to the enormous demand and insufficient production, could lead the CoV-19 to kill a large number of individuals. At present, there is no drug capable of treating CoV-19 flu, the only therapeutic remedies are those aimed at the side effects caused by the virus, such as inflammation and pulmonary fibrosis, recognized as the first causes of death. One of the COVID-19 treatments involves inhaling a mixture of gaseous hydrogen and oxygen, obtaining better results than with oxygen alone. It was also noted that individuals vaccinated for viral and/or bacterial infectious diseases were less likely to become infected. In addition, germicidal UV radiation "breaks down" the oxygen O2 which then aggregate into O3 (ozone) molecules creating the ozone layer, capable of inhibiting viral replication and improving lung respiration. All these precautions should be taken into consideration to lower the risk of infection by CoV-19. New anti-viral therapies with new drugs should also be taken into consideration. For example, microbes are known to bind TLR, inducing IL-1, a pleiotropic cytokine, highly inflammatory, mediator of fever and fibrosis. Therefore, drugs that suppress IL-1 or IL-1R, also used for the treatment of rheumatoid arthritis are to be taken into consideration to treat COVID-19. We strongly believe that all these devices described above can lead to greater survival and. therefore, reduction in mortality in patients infected with CoV-19.

Mast cells contribute to coronavirus-induced inflammation: new anti-inflammatory strategy.

Coronavirus can cause respiratory syndrome which to date has affected about twelve thousand individuals, especially in China. Coronavirus is interspecies and can also be transmitted from man to man, with an incubation ranging from 1 to 14 days. Human coronavirus infections can induce not only mild to severe respiratory diseases, but also inflammation, high fever, cough, acute respiratory tract infection and dysfunction of internal organs that may lead to death. Coronavirus infection (regardless of the various types of corona virus) is primarily attacked by immune cells including mast cells (MCs), which are located in the submucosa of the respiratory tract and in the nasal cavity and represent a barrier of protection against microorganisms. Viral activate MCs release early inflammatory chemical copounds including histamine and protease; while late activation provoke the generation of pro-inflammatory IL-1 family members including IL-1, IL-6 and IL-33. Here, we propose for the first time that inflammation by coronavirus maybe inhibited by anti-inflammatory cytokines belonging to the IL-1 family members.

Interrelationship between inflammatory cytokines (IL-1, IL-6, IL-33, IL-37) and acquired immunity.

It is now well-known that interleukins (ILs) play a pivotal role in shaping innate immunity: inflammatory ILs are responsible for all innate aspects of immune response, from the very first vascular reactions to the chronic non-specific response to inflammation; while anti-inflammatory ILs are responsible for keeping adaptive immunity at bay. The interactions between ILs and adaptive immunity have been long considered secondary to the effects on the innate immune system, but in recent years it has appeared more clearly that IL direct interactions with adaptive immunity are extremely important both in physiologic and pathologic immune response. In the present review we analyze the role of inflammatory ILs (IL-1, IL-6, IL-33 and IL-37) on adaptive immunity and briefly discuss the possible therapeutic perspectives of IL-blockade in adaptive immunity disorders.

Mesenchymal stem cells and IL-37: a powerful combination.

Mesenchymal stem cells (MSCs) are able to exert immunomodulatory and anti-inflammatory actions. Thanks to these properties, MSCs may be a promising alternative approach for the treatment of inflammatory disease. Important cytokines involved in inflammation are those included in the IL-1 family. Interleukin-37 (IL-37) is one of the member able to suppress both innate and adaptive immunity. Recently, it was found that MSCs and their derivatives can modulate IL-37, and MSCs expressing IL-37 seem to have an enhanced therapeutic efficacy.

Impact of mast cells in systemic lupus erythematosus: can inflammation be inhibited?

Systemic lupus erythematosus (SLE), is a complex chronic inflammatory autoimmune disease, with rheumatological manifestations, which afflicts mainly women. SLE presents various heterogeneous clinical aspects and different pathogeneses and involves the production of anti- DNA autoantibodies which are deposited as immune complexes in various organs and tissues, provoking inflammation. These diseases cause multiple tissue and organ damage in arthritis, skin lesions, hematologic changes, renal and neurologic disorders, and others (Table I). In SLE, serum contains anti-nucleus antibodies and anti-DNA antibodies that can be important biomarkers for patients suffering from this disease.

Gut microbiota and immunity in common variable immunodeficiency: crosstalk with pro-inflammatory cytokines.

In recent years, gut microbiota (GM) has emerged as a key factor in shaping the pathogenesis of a vast array of immune-mediated diseases, as well as in the response to immune-based treatments such as anti PD-1 and anti-CTLA4 therapy or influenza vaccination. In addition, GM has a significant role in the immune system development and is fundamental in developing mucosal immunity. Recent data suggest that GM plays an important role in the immune system of immune deficient patients. GM status has a remarkable impact on the immune system and in immune deficient patients; this can lead to important consequences. Prebiotics are indeed a promising candidate in restoring GM homeostasis and improving immunity. Antibiotics are also capable of altering the microbial equilibrium.

Interleukin-1 family cytokines and mast cells: activation and inhibition.

Activated mast cells (MCs) secrete a number of compounds including pro-inflammatory and anti-inflammatory cytokines. MCs are a potential source of cytokines and chemokines which participate in allergic reactions and inflammation. MCs can be activated by IgE through its receptor FceRI, but also by Toll-like receptors and/or interleukin (IL)-1. MCs can be a target for both pro-inflammatory and anti-inflammatory cytokines. IL-1 activates MCs to release inflammatory chemical mediators, and cytokines/chemokines, an effect which can be potentially inhibited by IL-37. In addition, IL-36 is also a powerful cytokine with a pro-inflammatory activity. IL-38 binds IL-36R and inhibits the pro-inflammatory activity of IL-36, thus performing a therapeutic action. In this article we review the role of MCs in relation to pro-inflammatory and anti-inflammatory IL-1 family member cytokines and a possible therapeutic effect in inflammatory disorders.

CAR-T cell therapy causes inflammation by IL-1 which activates inflammatory cytokine mast cells: anti-inflammatory role of IL-37.

Chimeric antigen receptor (CAR) T cells are genetically modified T cells that act against cancer. When CAR-T cells are administered they can trigger inflammatory cytokines and increase toxicity. Interleukin (IL)-1 is the classic cytokine that mediates inflammatory reactions including those that occur in CAR-T-cell therapy. IL-1 also induces IL-33 in mast cells (MCs), amplifying the allergic reaction. IL- 37 (ILF7) is an IL-1 family member which binds IL-18 receptor alpha (IL-18Rα) chain and suppresses innate and acquired immunity. IL-37 is an anti-inflammatory cytokine which inhibits pro-inflammatory cytokines including IL-1 and IL-33. Here, we hypothesize that inflammation and toxicity generated in tumor CAR-T therapy could be inhibited by IL-37, contributing to an improvement in the treatment of tumors with CAR-T therapy.

Stimulated mast cells release inflammatory cytokines: potential suppression and therapeutical aspects.

Mast cells (MCs) are derived from bone marrow precursors and are immune cells involved in acute and chronic inflammation. MCs are ubiquitous and play a crucial role in innate and acquired immunity. They are activated through cross-linking of their surface high affinity receptors (FcεRI), leading to immediate secretion of stored inflammatory mediators, and late production and release of pro-inflammatory cytokines/chemokines without degranulation. Therefore, MCs are important in inflammatory responses. Members of the interleukin (IL)-1 cytokine family, such as IL-1 and IL-33, and various antigens markedly increase IL-1 and tumor necrosis factor (TNF) expression and secretion from MCs. One of the latest cytokines is IL-33, an IL-1 family member acting via its ST2/IL-1R4, which has been shown to regulate MCs. IL-1 and IL-33 are cytokines found to be implicated in many inflammatory disorders including rheumatoid arthritis, atherosclerosis and psoriasis. In general, IL-1 family member cytokines play a pro-inflammatory role and increase the pathological state. IL-37 is a member of the IL-1 family with anti-inflammatory activity through inhibition of pro-inflammatory cytokines. IL-37 particularly suppresses IL-1-mediated innate inflammatory response, but also acts on the acquired immune response. IL-37 is activated by pro-inflammatory agents and cytokines, playing a protective role against inflammation. This cytokine is a natural regulator of immunity and is a therapeutic promise against inflammatory diseases. Since IL-1 is produced by and activates MCs to release IL-33 and TNF, here we hypothesize that MCs can be inhibited by IL-37 and therefore reduce their pro-inflammatory activity. However, the maturation, transport and secretion of IL-37 remain to be clarified.

IL-33 mediates allergy through mast cell activation: Potential inhibitory effect of certain cytokines.

Mast cells (MCs) are hematopoietic immune cells commonly found in adjacent to blood vessels in the lamina propria of airway mucosa. They are important in allergic reactions since the cross-linking of their surface high affinity receptor FceRI induces activation of these cells, and provokes the synthesis, degranulation and release of inflammatory mediators including arachidonic acid-derived eicosanoids (de novo synthesized), stored enzyme mediators, and inflammatory TH1 and TH2 cytokines, and chemokines. Interleukin (IL)-33 participates in innate and adaptive immunity and inflammation and, acting on CD34+ cells, causes MC differentiation and maturation. IL-33 is generated by activated immune cells, and activates MCs which degranulate and release pro-inflammatory mediators. IL-33 is very important in mediating allergic inflammation and can be induced by IL-1 beta. It is also called "alarmin" and is an inflammatory cytokine IL-1 family member, expressed from mocytes and MCs, which binds its receptor ST2, provoking its release after cell damage. MC-derived allergic compounds in response to IL-33 is critical to innate type 2 immunity. IL-37 is expressed by immune and non-immune cells after pro-inflammatory stimulus. IL-37, an anti-inflammatory cytokine, binds IL-18Ra and suppresses pro-inflammatory IL-1 beta released by activated immune cells such as macrophages. Here, we hypothesize that pro-inflammatory IL-1 family member cytokines released by activated MCs, mediating inflammatory allergic phenomenon, can be suppressed by IL-37.

Critical role of inflammatory mast cell in fibrosis: Potential therapeutic effect of IL-37.

BACKGROUND: Fibrosis involves the activation of inflammatory cells, leading to a decrease in physiological function of the affected organ or tissue. AIMS: To update and synthesize relevant information concerning fibrosis into a new hypothesis to explain the pathogenesis of fibrosis and propose potential novel therapeutic approaches. MATERIALS AND METHODS: Literature was reviewed and relevant information is discussed in the context of the pathogenesis of fibrosis. RESULTS: A number of cytokines and their mRNA are involved in the circulatory system and in organs of patients with fibrotic tissues. The profibrotic cytokines are generated by several activated immune cells, including fibroblasts and mast cells (MCs), which are important for tissue inflammatory responses to different types of injury. MC-derived TNF, IL-1, and IL-33 contribute crucially to the initiation of a cascade of the host defence mechanism(s), leading to the fibrosis process. Inhibition of TNF and inflammatory cytokines may slow the progression of fibrosis and improve the pathological status of the affected subject. IL-37 is generated by various types of immune cells and is an IL-1 family member protein. IL-37 is not a receptor antagonist; it binds IL-18 receptor alpha (IL-18Rα) and delivers the inhibitory signal by using TIR8. It has been shown that IL-37 can be protective in inflammation and injury, and inhibits both innate and adaptive immunity. DISCUSSION: IL-37 may be useful for suppression of inflammatory diseases induced by inhibiting MyD88-dependent TLR signalling. In addition, IL-37 downregulates NF-κB induced by TLR2 or TLR4 through a mechanism dependent on IL-18Rα. CONCLUSION: This review summarizes current knowledge on the role of MC in inflammation and tissue/organ fibrosis, with a focus on the therapeutic potential of IL-37-targeting cytokines.

Impact of mold on mast cell-cytokine immune response.

Molds include all species of microscopic fungi, the spores of which are small molecules, ubiquitous, mostly found in soil with higher rainfall and high humidity, in the atmosphere of urban and rural settings and in decaying vegetation. They originate from pathogenic fungi and have a crucial role in inflammatory response, causing a broad range of diseases. Immune suppressed subjects may develop mycoses caused by opportunistic common pathogenic fungi. Mast cells (MCs) are immune cells involved in the pathophysiology of infected skin, lung, and organs, where there is an increase of angiogenesis. Airways fungi infections can induce allergic lung disease mediated by MCs and other immune cells. In addition, fungal infection may cause and/or aggravate asthma inflammation. Spores are able to navigate in the airways of the lung and can be recognized trough toll-like receptor (TLR) signaling by the innate immune cells including MCs. Activated MCs release preformed mediators including histamine, proteases (tryptase, chimase), pro-inflammatory cytokines/chemokines and they also generate arachidonic acid products. MCs activated by fungi provoke an increases of PGD2 levels and lead to hypersensitivity diseases which present signs such as irritation of the respiratory tract and eyes, recurrent sinusitis, bronchitis, cough and neurological manifestations including fatigue, nausea, headaches and brain fog. Therefore, fungi activate the innate immune response through the TLRs, leading to the release of myeloid differentiation factor 88 (MyD88) which, with a series of cascade reactions, induces the stimulation of AP-1 and NF-kB with subsequent activation of inflammatory IL-1 family members. Here, we report that fungi can activate MCs to secrete pro-inflammatory cytokines which may be inhibited by IL-37, a new anti-inflammatory IL-1 family member.

New concepts in neuroinflammation: mast cells pro-inflammatory and anti-inflammatory cytokine mediators.

The activation of brain nociceptors and neurons may lead to neurogenic inflammation, an event that involves immune cells including mast cells (MCs). Microglia are similar to macrophages and secrete pro-inflammatory IL-1 family members and TNF. TNF is rapidly released (first 10 minutes from MC granules) and is subsequently secreted along with other pro-inflammatory cytokines with a new synthesis after several hours. MC-derived TNF is a very powerful pro-inflammatory cytokine which mediates sensitization of the meningeal nociceptors. Here, we report the involvement of MCs in neuroinflammation, the role of inflammatory cytokine IL-1 family members, and of TNF, as well as the potential inhibition of IL-37.

Low-grade chronic inflammation mediated by mast cells in fibromyalgia: role of IL-37.

It has been observed that acute stress causes the activation of TH1 cells, while TH2 cells regulate and act on chronic inflammation. Fibromyalgia (FM) is a chronic, idiopathic disorder which affects about twelve million people in the United States. FM is characterized by chronic widespread pain, fatigue, aching, joint stiffness, depression, cognitive dysfunction and non-restorative sleep. The mechanism of induction of muscle pain and inflammation is not yet clear. In FM there is an increase in reactivity of central neurons with increased sensitivity localized mainly in the CNS. Mast cells are involved in FM by releasing proinflammatory cytokines, chemokines, chemical mediators, and PGD2. TNF is a cytokine generated by MCs and its level is higher in FM. The inhibition of pro-inflammatory IL-1 family members and TNF by IL-37 in FM could have a therapeutic effect. Here, we report for the first time the relationship between MCs, inflammatory cytokines and the new anti-inflammatory cytokine IL-37 in FM.